Vibratory separators are used to separate differing sizes of materials in a flowing material stream during processing at a manufacturing facility. These vibratory separators incorporate removable screen assemblies which perform the separation of the materials. The material stream is provided to the vibratory screen in various forms including both dry and wet states. The material stream is provided to the screen assemblies where it impinges upon the screen surface of the screen assembly. The screens are then moved (vibrated) to cause the solids which have impinged upon the screen to be separated according to the size of the holes in the screen, as required in the screening operation. Materials passing through the screen proceed to further processing. Materials not passing the screen (termed oversized) are then removed from the screen and may be discarded or returned to the material stream.
The conventional screens provided to the vibratory loading machines are simple wire mesh units placed upon a base provided by the vibratory loading machine. The vibratory loading machine is then activated and set to the amount of vibration needed. To help in the alignment of the screen upon the vibratory loading machine, the conventional screens are equipped with mating holes that accept a dowel (or special proprietary pin) protruding from the top of the vibratory loading machine. When the screens are required to be removed/repaired or discarded, the screen is lifted from the vibratory loading machine such that the pin or dowel inserted into the frame of the screen exits the hole, thereby freeing the screen for removal. The screens are then replaced during the maintenance activity. As described above, the placement of a vibratory screen upon a vibratory loading device is accomplished in a one step process. There are significant drawbacks, however, to this single step installation and removal process. The first drawback of the current conventional screens and methods to install these screens is that although manufacturers attempt to make the vibratory loading machines in standard shapes and configurations, variations in the production of the vibratory loading machines occur during manufacturing. Vibratory loading machines also come in different shapes and arrangements; therefore conventional screens which are placed upon the vibratory loading machines often do not have a proper fit upon the mating surface of the vibratory loading machine. If misalignment is severe, the placement of the pin or dowel in the mating holes provided in the screen cannot occur and the operators of the manufacturing facility must augment the screens to properly secure the screens. The augmentation of the screening arrangements can be costly for users of such screens and in extreme cases full-time personnel must be employed to change and\or augment screens to allow the manufacturing facility to continue the material segregation process. This augmentation must often occur when the screen needs to be changed, and therefore production may be hampered due to the need for augmentation. Additionally, screens currently in production are expensive to produce as the structural components are often cumbersome and awkward to produce.
Current vibratory screen arrangements have other significant drawbacks. In general, the vibratory screen arrangements are placed upon the mating surface of a vibratory loading machine. During operation of the vibratory loading machine, the vibratory screen arrangements move in a predefined manner which can include several degrees of freedom of motion. During movement of the screening arrangements, materials often shift onto and off of the arrangements. Current vibratory screen arrangements do not provide any sealing mechanism between the vibratory screening arrangement and the vibratory screening machine. This lack of any sealing mechanism or capability often causes detrimental effects on the screening process.
Materials can flow from the top of the screen arrangement and by pass the screen arrangement in the non sealed locations. Materials by passing the screen arrangement, therefore, may not be properly sized and materials in the material stream leaving the screen may not be within prescribed process limitations.
There is therefore a need to provide a screen arrangement which will be easy to install on a vibratory loading machine and that will not require workers at the manufacturing facility to augment the screen during installation.
There is also a need to provide a vibratory screen arrangement which can be placed upon different configurations of vibratory loading machines which will allow the vibratory loading machines to operate at expected efficiencies.
There is a yet further need for a vibratory screen arrangement which provides a seal between the vibratory screening arrangement and the vibratory loading machine such that materials cannot transfer through the screening arrangement without passing through the screening material.
There is also a further need to provide a vibratory screen arrangement which is economical to produce and which will have a long service life for the environment in which the screen is placed.
There is a further need to provide a vibratory screen arrangement which will function under different structural loading conditions without degrading from anticipated vibratory loading cycles.